INDEX 383
Empty set: 1.1
Endless road: 9.12, prob. 3
Entire function: 9.3
£-Entropy of a set: 3.16, prob. 4
Equation of a hyperplane: 5.8
Equicontinuous at a point, equicontinuous:
7.5

Equipotentsets: 1.9
Equivalence class, equivalence relation: 1.8
Equivalent norms: 5.6
Equivalent roads: 9.6
Essential mapping: 9.Ap.2
Essential singular point, essential singu-
larity: 9.15

Euclidean distance: 3.2
Everywhere dense set: 3.9
Exponential function: 4.3 and 9.5
Extended real line: 3.3
Extension of a mapping: 1.4
Exterior point of a set, exterior of a set: 3.7
Extremity of an interval: 2.1
Extremity of a path: 9.6
Gram determinant: 6.6, prob. 3
Graph of a relation: 1.3
Graph of a mapping: 1.4
Greatest lower bound: 2.3
Green function of a Sturm-Liouville prob-
lem: 11.7
Gronwall's lemma: 10.5

H
Haar orthonormal system: 8.7, prob. 7
Hadamard's three circles theorem: 9.5,

prob. 10
Hadamard's gap theorem: 9.15, prob. 7
Hausdorff distance of two sets: 3.16, prob. 3
Hermitian form: 6.1
Hermitian kernel: 11.6
Hermitian norm: 9.5, prob. 7
Hermitian operator: 11.5
Hiibert basis: 6.5
Hilbert space: 6.2
Hiibert sum of Hilbert spaces: 6.4
Homeomorphic metric spaces, homeomor-

phism: 3.12;
Homogeneous linear differential equation:

10.8
Homogeneous hyperplane: 5.8, prob. 3
Homotopic paths, homotopic loops, homo-

topy of a path into a path: 9.6 and
10.2, prob. 6
Hyperplane: 5.8 and 5.8, prob. 3
Hyperplane of support: 5.8, prob. 3

I
Identity mapping: 1.4
Image of a set by a mapping: 1.5
Imaginary part of a complex number: 4.4
Implicit function theorem: 10.2
Improperly integrable function along an

endless road, improper integral: 9.12,
prob. 3
Increasing function: 4.2
Increasing on the right: 8.5, prob. 1
Indefinitely differentiable mapping: 8.12
Index of a point with respect to a circuit,

of a circuit with respect to a point: 9.8
Index of a point with respect to a loop:

9.Ap.l
Induced distance: 3.10
Inessential mapping: 9.Ap.2

Family of elements: 1.8
Finer distance, finer topology: 3.12
Finite number: 3.3
Fixed point theorem: 10.1
Fourier coefficient (nth): 6.5
Fredholm equation, Fredholm alternative:
11.6
Frobenius's theorem: 10.9
Frobenius-Perron's theorem: 11.1, prob. 6
Frontier point of a set, frontier of a set: 3.8
Full sequence of positive eigenvalues: 11.5,

prob. 8
Function: 1.4

Function of bounded variation: 7.6, prob. 3
Function of positive type: 6.3, prob. 4
Functional graph, functional relation: 1.4
Functions coinciding in a subset: 1.4
Fundamental system of neighborhoods:

3.6
Fundamental theorem of algebra: 9.11

Geometric multiplicity of an eigenvalue:
11.4
Goursat's theorem: 9.10, prob. 1